PORTLAND, Maine — The former executive director of the Maine Turnpike pleaded guilty Thursday to stealing tens of thousands of dollars of turnpike money over many years to pay for upscale hotels in Maine, Canada, the Caribbean and Europe, meals at fancy restaurants, and personal spa treatments.

Paul Violette, 56, pleaded guilty to a charge of theft for unauthorized use of turnpike gift cards and using turnpike authority credit cards for personal travel, meals and other expenses.

He will likely be sentenced in April. Prosecutors will ask for five years, but his attorney will seek a shorter sentence.

Violette was executive director of the Maine Turnpike Authority for 23 years before he resigned last March amid allegations of lavish spending and misappropriation of funds. The authority oversees the 109-mile Maine Turnpike.

“This is the biggest public corruption case I’ve seen in my 28 years of practice,” Assistant Attorney General Leanne Robbin said after the hearing. “This is a significant abuse of power.”

Violette agreed to own up to the charges and put the matter behind him, said Portland attorney Peter DeTroy, who represents Violette.

“Remorse has been there since day one,” DeTroy said after the hearing. “And obviously he has a lot of anxiety about what’s going to happen to him going forward. There’s also a tremendous sense of remorse of what this has done to his friends and family. He feels very embarrassed about what has happened.”

State Sen. Dawn Hill, D-York, led the independent investigation of the turnpike’s finances and operations that led to Violette’s resignation in March.

Robbin told Superior Court Justice Roland Cole that state officials have identified up to $230,000 of turnpike money that was potentially used for Violette’s personal expenses.

Violette had no comment after the hearing. He was accompanied by his brother, Tom, and his brother’s wife.

He sat grim-faced with his eyes closed Thursday as Robbin recited a list of hotels and boutique inns where he used turnpike money for stays in Maine, Quebec, New Brunswick, Massachusetts, Bermuda, Puerto Rico, Italy and France. He also used turnpike money to make a $1,000 deposit on a tuxedo, Robbin said.

Violette’s downfall stemmed from a report last year by the state Office of Program Evaluation and Government Accountability that looked at turnpike authority operations and finances. The authority is a quasi-governmental agency that runs the turnpike, which carries more than 60 million vehicles and generates $100 million or more in toll revenues a year.

The report scrutinized Violette’s purchase of hundreds of gift cards to upscale hotels and restaurants. Violette claimed he gave the cards to civic and charitable groups for fundraisers, but he couldn’t document his claims.

The Maine Turnpike Authority later filed a lawsuit against Violette accusing him of misusing nearly $500,000 in turnpike funds in the form of gift cards, credit card charges and vacation and sick leave pay to which he wasn’t entitled.

The complaint further said Violette was overpaid by $161,000 for unused vacation time and sick leave after falsely claiming he hadn’t taken any vacation or sick days during his 23 years at the agency.

The lawsuit was settled in December with the turnpike receiving $430,000 to cover its financial losses. Violette paid $155,000 of his own money — which was his estimated net worth — with two insurance companies paying the rest.

Robbin told the judge that Violette continued using turnpike authority gift cards and credit cards for his personal trips even after other turnpike officials confronted him in late 2005. But those employees didn’t take the matter any further, she said.

“MTA staff feared criticizing Violette or going to the (turnpike authority) board with their concerns,” she told Cole.

Violette’s criminal conviction represents a long fall from his previous public standing. He comes from a prominent political family from northern Maine and served as a state representative and senator before taking the top job at the turnpike.

“I don’t know what brought him to that place, but to me, I look at it as a prosecutor, and I see arrogance,” Robbin said outside of the courtroom.

DeTroy said he expects Violette to speak at his sentencing hearing, when he could offer an explanation for his actions.

Violette perhaps rationalized the spending as being OK, especially when some of it came before or after turnpike authority-sanctioned conferences in Europe, DeTroy said.

“You end up rationalizing things in your life, and I think he did,” he said.